Bird mite / Rodent mite

Scientific Name: Ornithonyssus sylviarum / Liponyssus sanguineus

Order & Family: Order: Mesostigmata, Family: Macronyssidae

Size: Extremely small, approximately 0.5 to 1.0 mm (about the size of a period at the end of a sentence).

Bird mite / Rodent mite

Natural Habitat

Typically found in bird nests (e.g., under eaves) or rodent burrows. They enter indoor spaces when their host moves away or dies, often found around windows, vents, or bedding.

Diet & Feeding

Blood of host animals (birds or rodents). They cannot complete their life cycle on human blood but will bite humans if a preferred host is unavailable.

Behavior Patterns

They are semi-persistent parasites that spend much of their time on the host or in the nesting material. They are most active at night and can crawl relatively long distances into homes searching for a food source.

Risks & Benefits

Risks: Their bites cause intense itching and small red rashes or welts in humans; though they don't transmit diseases to humans, they can cause significant psychological distress and skin irritation. Benefits: None to humans; they are strictly parasitic pests.

Identified on: 3/15/2026